Delta water getting saltier, fish kills show

Sardine-like fish that spend most of their lives in the ocean were sucked by the thousands into the south Delta export pumps near Tracy this spring.

Alex Breitler

Sardine-like fish that spend most of their lives in the ocean were sucked by the thousands into the south Delta export pumps near Tracy this spring.

While your life might not hinge on the wellbeing of Pacific herring, their presence deep in the Delta is evidence that the estuary is becoming saltier, which could be bad news for farmers if the drought persists.

Saltwater from San Francisco Bay is creeping farther than usual into the Delta this year because there has been little runoff from the mountains to keep the estuary fresh.

A total of 1,780 Pacific herring were entrained at the giant pumps, the most since the drought of 1976-77, said Carl Wilcox, a Delta policy advisor for the state Department of Fish and Wildlife.

"In all likelihood it's just a factor of the low outflow," Wilcox said.

Adult herring live in massive schools off the Pacific Coast, plunging to depths of up to 1,300 feet. They move to shallower brackish waters to spawn, which is why baby herring are sometimes found in the Delta.

Normally, however, they stay far to the west in Suisun Bay or perhaps near the confluence of the Sacramento and San Joaquin Rivers.

The Tracy pumps are much farther inland - 80 miles upstream of San Francisco Bay.

Based on surveys of tiny larvae, the number of herring killed at the pumps was "pretty minimal" compared with the total number of herring in the bay and Delta, Wilcox said.

And herring are not a threatened or endangered species, such as the infamous Delta smelt, whose demise at the pumps can trigger restrictions on how much water can be delivered to two-thirds of Californians.

Still, the mere presence of the herring says something about current conditions in the Delta.

Earlier this year, the state invoked emergency powers to relax rules that determine how much water must flow through the Delta. They did that so limited amounts of water could be pumped to parched farms and cities south of the Delta.

"I guess I'm not surprised" that herring were found at the pumps, said Jon Rosenfield, a biologist with environmental group The Bay Institute. "These fish are a casualty of the drought, but also of our relaxing of water quality standards. When you cut environmental protections, the environment suffers."

Herring are important to commercial fishermen in San Francisco Bay, and are a "huge" source of food for birds, Rosenfield said.

The real toll was probably much higher than 1,780 fish, he added, since the area near the pumps is a virtual buffet for hungry predatory fish like striped bass.

Of course, saltier water affects more than fish.

Stockton attorney Dante Nomellini, who represents Delta farmers, said the water does appear to be "fairly brackish" compared to past years - and is likely to only get saltier as the summer wears on.

Farmers can continue to pump Delta water onto their crops, but saltier water means saltier soil, Nomellini said.

That might not be such a big problem for mature crops that are already in the ground, he said. "But if we don't get that salt out of the ground for next year's planting, we'll have serious consequences," he said.

And getting the salt out of the soil will require either rain or an infusion of fresher Delta water that farmers can pump onto their fields.

As for the herring, if conditions don't improve, "I'm sure the sharks are going to move in right behind them," Nomellini said.

Contact reporter Alex Breitler at (209) 546-8295 or abreitler@recordnet.com. Follow him at recordnet.com/breitlerblog and on Twitter @alexbreitler.